lib/Kconfig

   1 #
   2 # Library configuration
   3 #
   4
   5 config BINARY_PRINTF
   6         def_bool n
   7
   8 menu "Library routines"
   9
  10 config RAID6_PQ
  11         tristate
  12
  13 config RAID6_PQ_BENCHMARK
  14         bool "Automatically choose fastest RAID6 PQ functions"
  15         depends on RAID6_PQ
  16         default y
  17         help
  18           Benchmark all available RAID6 PQ functions on init and choose the
  19           fastest one.
  20
  21 config PACKING
  22         bool "Generic bitfield packing and unpacking"
  23         default n
  24         help
  25           This option provides the packing() helper function, which permits
  26           converting bitfields between a CPU-usable representation and a
  27           memory representation that can have any combination of these quirks:
  28             - Is little endian (bytes are reversed within a 32-bit group)
  29             - The least-significant 32-bit word comes first (within a 64-bit
  30               group)
  31             - The most significant bit of a byte is at its right (bit 0 of a
  32               register description is numerically 2^7).
  33           Drivers may use these helpers to match the bit indices as described
  34           in the data sheets of the peripherals they are in control of.
  35
  36           When in doubt, say N.
  37
  38 config BITREVERSE
  39         tristate
  40
  41 config HAVE_ARCH_BITREVERSE
  42         bool
  43         default n
  44         depends on BITREVERSE
  45         help
  46           This option enables the use of hardware bit-reversal instructions on
  47           architectures which support such operations.
  48
  49 config GENERIC_STRNCPY_FROM_USER
  50         bool
  51
  52 config GENERIC_STRNLEN_USER
  53         bool
  54
  55 config GENERIC_NET_UTILS
  56         bool
  57
  58 config GENERIC_FIND_FIRST_BIT
  59         bool
  60
  61 source "lib/math/Kconfig"
  62
  63 config NO_GENERIC_PCI_IOPORT_MAP
  64         bool
  65
  66 config GENERIC_PCI_IOMAP
  67         bool
  68
  69 config GENERIC_IOMAP
  70         bool
  71         select GENERIC_PCI_IOMAP
  72
  73 config STMP_DEVICE
  74         bool
  75
  76 config ARCH_USE_CMPXCHG_LOCKREF
  77         bool
  78
  79 config ARCH_HAS_FAST_MULTIPLIER
  80         bool
  81
  82 config INDIRECT_PIO
  83         bool "Access I/O in non-MMIO mode"
  84         depends on ARM64
  85         help
  86           On some platforms where no separate I/O space exists, there are I/O
  87           hosts which can not be accessed in MMIO mode. Using the logical PIO
  88           mechanism, the host-local I/O resource can be mapped into system
  89           logic PIO space shared with MMIO hosts, such as PCI/PCIe, then the
  90           system can access the I/O devices with the mapped-logic PIO through
  91           I/O accessors.
  92
  93           This way has relatively little I/O performance cost. Please make
  94           sure your devices really need this configure item enabled.
  95
  96           When in doubt, say N.
  97
  98 config CRC_CCITT
  99         tristate "CRC-CCITT functions"
 100         help
 101           This option is provided for the case where no in-kernel-tree
 102           modules require CRC-CCITT functions, but a module built outside
 103           the kernel tree does. Such modules that use library CRC-CCITT
 104           functions require M here.
 105
 106 config CRC16
 107         tristate "CRC16 functions"
 108         help
 109           This option is provided for the case where no in-kernel-tree
 110           modules require CRC16 functions, but a module built outside
 111           the kernel tree does. Such modules that use library CRC16
 112           functions require M here.
 113
 114 config CRC_T10DIF
 115         tristate "CRC calculation for the T10 Data Integrity Field"
 116         select CRYPTO
 117         select CRYPTO_CRCT10DIF
 118         help
 119           This option is only needed if a module that's not in the
 120           kernel tree needs to calculate CRC checks for use with the
 121           SCSI data integrity subsystem.
 122
 123 config CRC_ITU_T
 124         tristate "CRC ITU-T V.41 functions"
 125         help
 126           This option is provided for the case where no in-kernel-tree
 127           modules require CRC ITU-T V.41 functions, but a module built outside
 128           the kernel tree does. Such modules that use library CRC ITU-T V.41
 129           functions require M here.
 130
 131 config CRC32
 132         tristate "CRC32/CRC32c functions"
 133         default y
 134         select BITREVERSE
 135         help
 136           This option is provided for the case where no in-kernel-tree
 137           modules require CRC32/CRC32c functions, but a module built outside
 138           the kernel tree does. Such modules that use library CRC32/CRC32c
 139           functions require M here.
 140
 141 config CRC32_SELFTEST
 142         tristate "CRC32 perform self test on init"
 143         depends on CRC32
 144         help
 145           This option enables the CRC32 library functions to perform a
 146           self test on initialization. The self test computes crc32_le
 147           and crc32_be over byte strings with random alignment and length
 148           and computes the total elapsed time and number of bytes processed.
 149
 150 choice
 151         prompt "CRC32 implementation"
 152         depends on CRC32
 153         default CRC32_SLICEBY8
 154         help
 155           This option allows a kernel builder to override the default choice
 156           of CRC32 algorithm.  Choose the default ("slice by 8") unless you
 157           know that you need one of the others.
 158
 159 config CRC32_SLICEBY8
 160         bool "Slice by 8 bytes"
 161         help
 162           Calculate checksum 8 bytes at a time with a clever slicing algorithm.
 163           This is the fastest algorithm, but comes with a 8KiB lookup table.
 164           Most modern processors have enough cache to hold this table without
 165           thrashing the cache.
 166
 167           This is the default implementation choice.  Choose this one unless
 168           you have a good reason not to.
 169
 170 config CRC32_SLICEBY4
 171         bool "Slice by 4 bytes"
 172         help
 173           Calculate checksum 4 bytes at a time with a clever slicing algorithm.
 174           This is a bit slower than slice by 8, but has a smaller 4KiB lookup
 175           table.
 176
 177           Only choose this option if you know what you are doing.
 178
 179 config CRC32_SARWATE
 180         bool "Sarwate's Algorithm (one byte at a time)"
 181         help
 182           Calculate checksum a byte at a time using Sarwate's algorithm.  This
 183           is not particularly fast, but has a small 256 byte lookup table.
 184
 185           Only choose this option if you know what you are doing.
 186
 187 config CRC32_BIT
 188         bool "Classic Algorithm (one bit at a time)"
 189         help
 190           Calculate checksum one bit at a time.  This is VERY slow, but has
 191           no lookup table.  This is provided as a debugging option.
 192
 193           Only choose this option if you are debugging crc32.
 194
 195 endchoice
 196
 197 config CRC64
 198         tristate "CRC64 functions"
 199         help
 200           This option is provided for the case where no in-kernel-tree
 201           modules require CRC64 functions, but a module built outside
 202           the kernel tree does. Such modules that use library CRC64
 203           functions require M here.
 204
 205 config CRC4
 206         tristate "CRC4 functions"
 207         help
 208           This option is provided for the case where no in-kernel-tree
 209           modules require CRC4 functions, but a module built outside
 210           the kernel tree does. Such modules that use library CRC4
 211           functions require M here.
 212
 213 config CRC7
 214         tristate "CRC7 functions"
 215         help
 216           This option is provided for the case where no in-kernel-tree
 217           modules require CRC7 functions, but a module built outside
 218           the kernel tree does. Such modules that use library CRC7
 219           functions require M here.
 220
 221 config LIBCRC32C
 222         tristate "CRC32c (Castagnoli, et al) Cyclic Redundancy-Check"
 223         select CRYPTO
 224         select CRYPTO_CRC32C
 225         help
 226           This option is provided for the case where no in-kernel-tree
 227           modules require CRC32c functions, but a module built outside the
 228           kernel tree does. Such modules that use library CRC32c functions
 229           require M here.  See Castagnoli93.
 230           Module will be libcrc32c.
 231
 232 config CRC8
 233         tristate "CRC8 function"
 234         help
 235           This option provides CRC8 function. Drivers may select this
 236           when they need to do cyclic redundancy check according CRC8
 237           algorithm. Module will be called crc8.
 238
 239 config XXHASH
 240         tristate
 241
 242 config AUDIT_GENERIC
 243         bool
 244         depends on AUDIT && !AUDIT_ARCH
 245         default y
 246
 247 config AUDIT_ARCH_COMPAT_GENERIC
 248         bool
 249         default n
 250
 251 config AUDIT_COMPAT_GENERIC
 252         bool
 253         depends on AUDIT_GENERIC && AUDIT_ARCH_COMPAT_GENERIC && COMPAT
 254         default y
 255
 256 config RANDOM32_SELFTEST
 257         bool "PRNG perform self test on init"
 258         help
 259           This option enables the 32 bit PRNG library functions to perform a
 260           self test on initialization.
 261
 262 #
 263 # compression support is select'ed if needed
 264 #
 265 config 842_COMPRESS
 266         select CRC32
 267         tristate
 268
 269 config 842_DECOMPRESS
 270         select CRC32
 271         tristate
 272
 273 config ZLIB_INFLATE
 274         tristate
 275
 276 config ZLIB_DEFLATE
 277         tristate
 278         select BITREVERSE
 279
 280 config LZO_COMPRESS
 281         tristate
 282
 283 config LZO_DECOMPRESS
 284         tristate
 285
 286 config LZ4_COMPRESS
 287         tristate
 288
 289 config LZ4HC_COMPRESS
 290         tristate
 291
 292 config LZ4_DECOMPRESS
 293         tristate
 294
 295 config ZSTD_COMPRESS
 296         select XXHASH
 297         tristate
 298
 299 config ZSTD_DECOMPRESS
 300         select XXHASH
 301         tristate
 302
 303 source "lib/xz/Kconfig"
 304
 305 #
 306 # These all provide a common interface (hence the apparent duplication with
 307 # ZLIB_INFLATE; DECOMPRESS_GZIP is just a wrapper.)
 308 #
 309 config DECOMPRESS_GZIP
 310         select ZLIB_INFLATE
 311         tristate
 312
 313 config DECOMPRESS_BZIP2
 314         tristate
 315
 316 config DECOMPRESS_LZMA
 317         tristate
 318
 319 config DECOMPRESS_XZ
 320         select XZ_DEC
 321         tristate
 322
 323 config DECOMPRESS_LZO
 324         select LZO_DECOMPRESS
 325         tristate
 326
 327 config DECOMPRESS_LZ4
 328         select LZ4_DECOMPRESS
 329         tristate
 330
 331 #
 332 # Generic allocator support is selected if needed
 333 #
 334 config GENERIC_ALLOCATOR
 335         bool
 336
 337 #
 338 # reed solomon support is select'ed if needed
 339 #
 340 config REED_SOLOMON
 341         tristate
 342
 343 config REED_SOLOMON_ENC8
 344         bool
 345
 346 config REED_SOLOMON_DEC8
 347         bool
 348
 349 config REED_SOLOMON_ENC16
 350         bool
 351
 352 config REED_SOLOMON_DEC16
 353         bool
 354
 355 #
 356 # BCH support is selected if needed
 357 #
 358 config BCH
 359         tristate
 360
 361 config BCH_CONST_PARAMS
 362         bool
 363         help
 364           Drivers may select this option to force specific constant
 365           values for parameters 'm' (Galois field order) and 't'
 366           (error correction capability). Those specific values must
 367           be set by declaring default values for symbols BCH_CONST_M
 368           and BCH_CONST_T.
 369           Doing so will enable extra compiler optimizations,
 370           improving encoding and decoding performance up to 2x for
 371           usual (m,t) values (typically such that m*t < 200).
 372           When this option is selected, the BCH library supports
 373           only a single (m,t) configuration. This is mainly useful
 374           for NAND flash board drivers requiring known, fixed BCH
 375           parameters.
 376
 377 config BCH_CONST_M
 378         int
 379         range 5 15
 380         help
 381           Constant value for Galois field order 'm'. If 'k' is the
 382           number of data bits to protect, 'm' should be chosen such
 383           that (k + m*t) <= 2**m - 1.
 384           Drivers should declare a default value for this symbol if
 385           they select option BCH_CONST_PARAMS.
 386
 387 config BCH_CONST_T
 388         int
 389         help
 390           Constant value for error correction capability in bits 't'.
 391           Drivers should declare a default value for this symbol if
 392           they select option BCH_CONST_PARAMS.
 393
 394 #
 395 # Textsearch support is select'ed if needed
 396 #
 397 config TEXTSEARCH
 398         bool
 399
 400 config TEXTSEARCH_KMP
 401         tristate
 402
 403 config TEXTSEARCH_BM
 404         tristate
 405
 406 config TEXTSEARCH_FSM
 407         tristate
 408
 409 config BTREE
 410         bool
 411
 412 config INTERVAL_TREE
 413         bool
 414         help
 415           Simple, embeddable, interval-tree. Can find the start of an
 416           overlapping range in log(n) time and then iterate over all
 417           overlapping nodes. The algorithm is implemented as an
 418           augmented rbtree.
 419
 420           See:
 421
 422                 Documentation/rbtree.txt
 423
 424           for more information.
 425
 426 config XARRAY_MULTI
 427         bool
 428         help
 429           Support entries which occupy multiple consecutive indices in the
 430           XArray.
 431
 432 config ASSOCIATIVE_ARRAY
 433         bool
 434         help
 435           Generic associative array.  Can be searched and iterated over whilst
 436           it is being modified.  It is also reasonably quick to search and
 437           modify.  The algorithms are non-recursive, and the trees are highly
 438           capacious.
 439
 440           See:
 441
 442                 Documentation/core-api/assoc_array.rst
 443
 444           for more information.
 445
 446 config HAS_IOMEM
 447         bool
 448         depends on !NO_IOMEM
 449         select GENERIC_IO
 450         default y
 451
 452 config HAS_IOPORT_MAP
 453         bool
 454         depends on HAS_IOMEM && !NO_IOPORT_MAP
 455         default y
 456
 457 source "kernel/dma/Kconfig"
 458
 459 config SGL_ALLOC
 460         bool
 461         default n
 462
 463 config IOMMU_HELPER
 464         bool
 465
 466 config CHECK_SIGNATURE
 467         bool
 468
 469 config CPUMASK_OFFSTACK
 470         bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS
 471         help
 472           Use dynamic allocation for cpumask_var_t, instead of putting
 473           them on the stack.  This is a bit more expensive, but avoids
 474           stack overflow.
 475
 476 config CPU_RMAP
 477         bool
 478         depends on SMP
 479
 480 config DQL
 481         bool
 482
 483 config GLOB
 484         bool
 485 #       This actually supports modular compilation, but the module overhead
 486 #       is ridiculous for the amount of code involved.  Until an out-of-tree
 487 #       driver asks for it, we'll just link it directly it into the kernel
 488 #       when required.  Since we're ignoring out-of-tree users, there's also
 489 #       no need bother prompting for a manual decision:
 490 #       prompt "glob_match() function"
 491         help
 492           This option provides a glob_match function for performing
 493           simple text pattern matching.  It originated in the ATA code
 494           to blacklist particular drive models, but other device drivers
 495           may need similar functionality.
 496
 497           All drivers in the Linux kernel tree that require this function
 498           should automatically select this option.  Say N unless you
 499           are compiling an out-of tree driver which tells you that it
 500           depends on this.
 501
 502 config GLOB_SELFTEST
 503         tristate "glob self-test on init"
 504         depends on GLOB
 505         help
 506           This option enables a simple self-test of the glob_match
 507           function on startup.  It is primarily useful for people
 508           working on the code to ensure they haven't introduced any
 509           regressions.
 510
 511           It only adds a little bit of code and slows kernel boot (or
 512           module load) by a small amount, so you're welcome to play with
 513           it, but you probably don't need it.
 514
 515 #
 516 # Netlink attribute parsing support is select'ed if needed
 517 #
 518 config NLATTR
 519         bool
 520
 521 #
 522 # Generic 64-bit atomic support is selected if needed
 523 #
 524 config GENERIC_ATOMIC64
 525        bool
 526
 527 config LRU_CACHE
 528         tristate
 529
 530 config CLZ_TAB
 531         bool
 532
 533 config DDR
 534         bool "JEDEC DDR data"
 535         help
 536           Data from JEDEC specs for DDR SDRAM memories,
 537           particularly the AC timing parameters and addressing
 538           information. This data is useful for drivers handling
 539           DDR SDRAM controllers.
 540
 541 config IRQ_POLL
 542         bool "IRQ polling library"
 543         help
 544           Helper library to poll interrupt mitigation using polling.
 545
 546 config MPILIB
 547         tristate
 548         select CLZ_TAB
 549         help
 550           Multiprecision maths library from GnuPG.
 551           It is used to implement RSA digital signature verification,
 552           which is used by IMA/EVM digital signature extension.
 553
 554 config SIGNATURE
 555         tristate
 556         depends on KEYS
 557         select CRYPTO
 558         select CRYPTO_SHA1
 559         select MPILIB
 560         help
 561           Digital signature verification. Currently only RSA is supported.
 562           Implementation is done using GnuPG MPI library
 563
 564 #
 565 # libfdt files, only selected if needed.
 566 #
 567 config LIBFDT
 568         bool
 569
 570 config OID_REGISTRY
 571         tristate
 572         help
 573           Enable fast lookup object identifier registry.
 574
 575 config UCS2_STRING
 576         tristate
 577
 578 source "lib/fonts/Kconfig"
 579
 580 config SG_SPLIT
 581         def_bool n
 582         help
 583          Provides a helper to split scatterlists into chunks, each chunk being
 584          a scatterlist. This should be selected by a driver or an API which
 585          whishes to split a scatterlist amongst multiple DMA channels.
 586
 587 config SG_POOL
 588         def_bool n
 589         help
 590          Provides a helper to allocate chained scatterlists. This should be
 591          selected by a driver or an API which whishes to allocate chained
 592          scatterlist.
 593
 594 #
 595 # sg chaining option
 596 #
 597
 598 config ARCH_NO_SG_CHAIN
 599         def_bool n
 600
 601 config ARCH_HAS_PMEM_API
 602         bool
 603
 604 config ARCH_HAS_UACCESS_FLUSHCACHE
 605         bool
 606
 607 config ARCH_HAS_UACCESS_MCSAFE
 608         bool
 609
 610 # Temporary. Goes away when all archs are cleaned up
 611 config ARCH_STACKWALK
 612        bool
 613
 614 config STACKDEPOT
 615         bool
 616         select STACKTRACE
 617
 618 config SBITMAP
 619         bool
 620
 621 config PARMAN
 622         tristate "parman" if COMPILE_TEST
 623
 624 config STRING_SELFTEST
 625         tristate "Test string functions"
 626
 627 endmenu
 628
 629 config GENERIC_LIB_ASHLDI3
 630         bool
 631
 632 config GENERIC_LIB_ASHRDI3
 633         bool
 634
 635 config GENERIC_LIB_LSHRDI3
 636         bool
 637
 638 config GENERIC_LIB_MULDI3
 639         bool
 640
 641 config GENERIC_LIB_CMPDI2
 642         bool
 643
 644 config GENERIC_LIB_UCMPDI2
 645         bool
 646
 647 config OBJAGG
 648         tristate "objagg" if COMPILE_TEST